From decf63336e356423300b935afbebeca1fcb15184 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong <guangrong.xiao@linux.intel.com> Date: Tue, 14 Apr 2015 12:04:10 +0800 Subject: [PATCH] KVM: MMU: fix comment in kvm_mmu_zap_collapsible_spte Soft mmu uses direct shadow page to fill guest large mapping with small pages if huge mapping is disallowed on host. So zapping direct shadow page works well both for soft mmu and hard mmu, it's just less widely applicable. Fix the comment to reflect this. Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Message-Id: <552C91BA.1010703@linux.intel.com> [Fix comment wording further. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/mmu.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 07bb22157338d..d43867c33bc4e 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4481,9 +4481,11 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, pfn = spte_to_pfn(*sptep); /* - * Only EPT supported for now; otherwise, one would need to - * find out efficiently whether the guest page tables are - * also using huge pages. + * We cannot do huge page mapping for indirect shadow pages, + * which are found on the last rmap (level = 1) when not using + * tdp; such shadow pages are synced with the page table in + * the guest, and the guest page table is using 4K page size + * mapping if the indirect sp has level = 1. */ if (sp->role.direct && !kvm_is_reserved_pfn(pfn) &&